view hgext3rd/topic/topicmap.py @ 4722:7839720c7c75

rewind: make sure merge commits include files from p1 and p2

Otherwise rewinding a merge commit makes it lose all changes.

This fix populates `updates` argument of rewriteutil.rewrite() with parent
changesets. That argument is normally used for folding multiple changesets, but
in this case it's simply used to include files from p1 and p2. Usually,
rewrite() works fine using ctx.files(), but that function can return an empty
list when ctx is a merge commit.

import contextlib
import hashlib

from mercurial.i18n import _
from mercurial.node import nullid
from mercurial import (
    branchmap,
    changegroup,
    cmdutil,
    extensions,
    repoview,
    util,
)

from . import (
    common,
)

basefilter = set(['base', 'immutable'])
def topicfilter(name):
    """return a "topic" version of a filter level"""
    if name in basefilter:
        return name
    elif name is None:
        return None
    elif name.endswith('-topic'):
        return name
    else:
        return name + '-topic'

def istopicfilter(filtername):
    if filtername is None:
        return False
    return filtername.endswith('-topic')

def gettopicrepo(repo):
    if not common.hastopicext(repo):
        return repo
    filtername = topicfilter(repo.filtername)
    if filtername == repo.filtername:
        return repo
    return repo.filtered(filtername)

def _setuptopicfilter(ui):
    """extend the filter related mapping with topic related one"""
    funcmap = repoview.filtertable
    partialmap = branchmap.subsettable

    # filter level not affected by topic that we should not override

    for plainname in list(funcmap):
        newfilter = topicfilter(plainname)
        if newfilter == plainname:
            continue

        def revsfunc(repo, name=plainname):
            return repoview.filterrevs(repo, name)

        base = topicfilter(partialmap[plainname])

        if newfilter not in funcmap:
            funcmap[newfilter] = revsfunc
            partialmap[newfilter] = base
    funcmap['unfiltered-topic'] = lambda repo: frozenset()
    partialmap['unfiltered-topic'] = 'visible-topic'

def _phaseshash(repo, maxrev):
    """uniq ID for a phase matching a set of rev"""
    revs = set()
    cl = repo.changelog
    fr = cl.filteredrevs
    nm = cl.nodemap
    for roots in repo._phasecache.phaseroots[1:]:
        for n in roots:
            r = nm.get(n)
            if r not in fr and r < maxrev:
                revs.add(r)
    key = nullid
    revs = sorted(revs)
    if revs:
        s = hashlib.sha1()
        for rev in revs:
            s.update('%s;' % rev)
        key = s.digest()
    return key

def modsetup(ui):
    """call at uisetup time to install various wrappings"""
    _setuptopicfilter(ui)
    _wrapbmcache(ui)
    extensions.wrapfunction(changegroup.cg1unpacker, 'apply', cgapply)
    extensions.wrapfunction(cmdutil, 'commitstatus', commitstatus)

def cgapply(orig, self, repo, *args, **kwargs):
    """make sure a topicmap is used when applying a changegroup"""
    other = repo.filtered(topicfilter(repo.filtername))
    return orig(self, other, *args, **kwargs)

def commitstatus(orig, repo, node, branch, bheads=None, opts=None):
    # wrap commit status use the topic branch heads
    ctx = repo[node]
    if ctx.topic() and ctx.branch() == branch:
        bheads = repo.branchheads("%s:%s" % (branch, ctx.topic()))

    ret = orig(repo, node, branch, bheads=bheads, opts=opts)

    # logic copy-pasted from cmdutil.commitstatus()
    if opts is None:
        opts = {}
    if ctx.topic():
        return ret
    parents = ctx.parents()

    if (not opts.get('amend') and bheads and node not in bheads and not
        [x for x in parents if x.node() in bheads and x.branch() == branch]):
        repo.ui.status(_("(consider using topic for lightweight branches."
                         " See 'hg help topic')\n"))

    return ret

def _wrapbmcache(ui):
    class topiccache(_topiccache, branchmap.branchcache):
        pass
    branchmap.branchcache = topiccache

    try:
        # Mercurial 4.9
        class remotetopiccache(_topiccache, branchmap.remotebranchcache):
            pass
        branchmap.remotebranchcache = remotetopiccache

        def _wrapupdatebmcachemethod(orig, self, repo):
            # pass in the bound method as the original
            return _wrapupdatebmcache(orig.__get__(self), repo)
        extensions.wrapfunction(branchmap.BranchMapCache, 'updatecache', _wrapupdatebmcachemethod)
    except AttributeError:
        # Mercurial 4.8 and before
        extensions.wrapfunction(branchmap, 'updatecache', _wrapupdatebmcache)


def _wrapupdatebmcache(orig, repo):
    previous = getattr(repo, '_autobranchmaptopic', False)
    try:
        repo._autobranchmaptopic = False
        return orig(repo)
    finally:
        repo._autobranchmaptopic = previous

# needed to prevent reference used for 'super()' call using in branchmap.py to
# no go into cycle. (yes, URG)
_oldbranchmap = branchmap.branchcache

@contextlib.contextmanager
def oldbranchmap():
    previous = branchmap.branchcache
    try:
        branchmap.branchcache = _oldbranchmap
        yield
    finally:
        branchmap.branchcache = previous

class _topiccache(object): # combine me with branchmap.branchcache

    def __init__(self, *args, **kwargs):
        # super() call may fail otherwise
        with oldbranchmap():
            super(_topiccache, self).__init__(*args, **kwargs)
        self.phaseshash = None

    def copy(self):
        """return an deep copy of the branchcache object"""
        if util.safehasattr(self, '_entries'):
            _entries = self._entries
        else:
            # hg <= 4.9 (624d6683c705, b137a6793c51)
            _entries = self
        new = self.__class__(_entries, self.tipnode, self.tiprev,
                             self.filteredhash, self._closednodes)
        new.phaseshash = self.phaseshash
        return new

    def branchtip(self, branch, topic=''):
        '''Return the tipmost open head on branch head, otherwise return the
        tipmost closed head on branch.
        Raise KeyError for unknown branch.'''
        if topic:
            branch = '%s:%s' % (branch, topic)
        return super(_topiccache, self).branchtip(branch)

    def branchheads(self, branch, closed=False, topic=''):
        if topic:
            branch = '%s:%s' % (branch, topic)
        return super(_topiccache, self).branchheads(branch, closed=closed)

    def validfor(self, repo):
        """Is the cache content valid regarding a repo

        - False when cached tipnode is unknown or if we detect a strip.
        - True when cache is up to date or a subset of current repo."""
        valid = super(_topiccache, self).validfor(repo)
        if not valid:
            return False
        elif not istopicfilter(repo.filtername) or self.phaseshash is None:
            # phasehash at None means this is a branchmap
            # come from non topic thing
            return True
        else:
            try:
                valid = self.phaseshash == _phaseshash(repo, self.tiprev)
                return valid
            except IndexError:
                return False

    def write(self, repo):
        # we expect mutable set to be small enough to be that computing it all
        # the time will be fast enough
        if not istopicfilter(repo.filtername):
            super(_topiccache, self).write(repo)

    def update(self, repo, revgen):
        """Given a branchhead cache, self, that may have extra nodes or be
        missing heads, and a generator of nodes that are strictly a superset of
        heads missing, this function updates self to be correct.
        """
        if not istopicfilter(repo.filtername):
            return super(_topiccache, self).update(repo, revgen)
        unfi = repo.unfiltered()
        oldgetbranchinfo = unfi.revbranchcache().branchinfo

        def branchinfo(r, changelog=None):
            info = oldgetbranchinfo(r)
            topic = ''
            ctx = unfi[r]
            if ctx.mutable():
                topic = ctx.topic()
            branch = info[0]
            if topic:
                branch = '%s:%s' % (branch, topic)
            return (branch, info[1])
        try:
            unfi.revbranchcache().branchinfo = branchinfo
            super(_topiccache, self).update(repo, revgen)
            self.phaseshash = _phaseshash(repo, self.tiprev)
        finally:
            unfi.revbranchcache().branchinfo = oldgetbranchinfo